Field of the Invention
The invention relates to an assembly and a method for supplying electrical energy to electrical traction motors in a rail vehicle, in particular a train set. The rail vehicle can in particular be a locomotive driven by a diesel-electrical drive unit or a rail vehicle that is part of a train set driven by a diesel-electrical drive unit.
Description of Related Art
Diesel-electrical drive units typically supply electrical energy to the traction motors and other consumers in the rail vehicle or train set by means of a generator, which is driven by the diesel engine and generates the electrical energy, wherein the generator is connected to a direct voltage intermediate circuit. Provision is made of at least one traction inverter for the traction motors and of at least one consumer inverter for the other consumers. The inverters generate alternating voltage or alternating current from the direct voltage of the intermediate circuit. However, it is also possible to connect DC traction motors and/or other DC consumers directly to the intermediate circuit without the interconnection of an inverter.
For the consumers, provision is made of a consumer connection that transfers the electrical energy from the consumer inverter or directly from the intermediate circuit to the consumer or consumers. The consumer connection can in particular be a connection comprising a so-called train current busbar. Hence the consumers are in particular ones that are employed for functions other than driving the rail vehicle or the train set such as heating, lighting, and/or air conditioning. For example, the assembly comprises the portion of a train current busbar that is arranged in the locomotive of a train set.
The invention relates in particular to assemblies or methods that have been described previously.
DE 101 03 538 B4 describes an electric motor-driven rail vehicle with an internal combustion engine. In normal operation (traction of the rail vehicle), a generator/motor system supplies a 3-phase alternating voltage to a pulse rectifier that feeds a direct voltage intermediate circuit. The direct voltage intermediate circuit can feed a DC motor or one or more three-phase drive motors via an inverter. The internal combustion engine and the generator, which can be a synchronous machine with either permanent magnet excitation or separate excitation or an asynchronous machine, are mechanically coupled to one another. Upon braking the electric motor-powered rail vehicle, the generator/motor system works in motorized operation and braking energy is thus introduced into the internal combustion engine.
Braking energy, which is supplied to the internal combustion engine, brings about an increase in the kinetic energy, i.e., the speed, and is also partially dissipated as heat. The internal combustion engine, especially when it is already running at high or medium speed right before braking, can only absorb a little braking energy. This is also true if the braking process is more protracted. The amount of continuous braking power that can be introduced into the internal combustion engine is small.